What is this strange encoder motor?
 

Tim Wescott wrote:

On 08/02/2010 06:48 PM, Ignoramus18921 wrote:
On 2010-08-03, Tim wrote:
On 08/02/2010 04:50 PM, Ignoramus18921 wrote:
Lots of new pictures here.

[much snipping]

Tim, how much angular accuracy could I get from this resolver, in
pulses per revolution?

Um -- pretty damn good?

It's hard to say, because it varies with the resolver. But I'd expect
anywhere between one and ten minutes of an arc (no, you don't get
dimensions in degrees, or counts, when you're dealing with resolvers).
Resolvers that do better than that generally go to "multi-speed" units,
with a "high-speed" resolver that repeats itself 8, 16, or 32 times
around the circle, and a "low-speed" (1x) resolver to tell you what
quadrant of the high-speed resolver you're looking at.


Iggy has a resolver, is it safe to say that an Inductosyn linear scale is the same type of
device? I'm curious since I have a sick id od grinder at work that still has some issues
after replacing the sliding head for the scale.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

What is this strange encoder motor?
 

On Tue, 03 Aug 2010 17:59:44 -0400, Wes
wrote:

Iggy has a resolver, is it safe to say that an Inductosyn linear scale is the same type of
device? I'm curious since I have a sick id od grinder at work that still has some issues
after replacing the sliding head for the scale.

Wes
It's the same thing, just laid out flat.

db

What is this strange encoder motor?
 

On 2010-08-03, Wes wrote:
Tim Wescott wrote:

On 08/02/2010 06:48 PM, Ignoramus18921 wrote:
On 2010-08-03, Tim wrote:
On 08/02/2010 04:50 PM, Ignoramus18921 wrote:
Lots of new pictures here.

[much snipping]

Tim, how much angular accuracy could I get from this resolver, in
pulses per revolution?

Um -- pretty damn good?

It's hard to say, because it varies with the resolver. But I'd expect
anywhere between one and ten minutes of an arc (no, you don't get
dimensions in degrees, or counts, when you're dealing with resolvers).
Resolvers that do better than that generally go to "multi-speed" units,
with a "high-speed" resolver that repeats itself 8, 16, or 32 times
around the circle, and a "low-speed" (1x) resolver to tell you what
quadrant of the high-speed resolver you're looking at.


Iggy has a resolver, is it safe to say that an Inductosyn linear scale is the same type of
device? I'm curious since I have a sick id od grinder at work that still has some issues
after replacing the sliding head for the scale.

Jon might know, I have no clue. Who made that Inductosyn?

What is this strange encoder motor?
 

Ignoramus30076 wrote:

Iggy has a resolver, is it safe to say that an Inductosyn linear scale is the same type of
device? I'm curious since I have a sick id od grinder at work that still has some issues
after replacing the sliding head for the scale.


Jon might know, I have no clue. Who made that Inductosyn?

An Inductosyn is similar in concept to a resolver, where a coil is
energized with an AC field, and by varying magnetic coupling to other
coils the position is detected. Inductosyn is a registered trademark of
Farrand Controls, but their patent has run out. The classic Inductosyn
has an exciting winding consisting of a serpentine trace on a PC board
like material. Very close to this is another short piece with two
serpentine traces of the same pitch a the spar. The two traces are
offset by 1/4 of a pitch, to provide the quadrature relationship.

The problem with the Inductosyn is that it takes a LOT of drive current
to provide a useful signal from the sense windings, often several amps
of drive.

Jon